BMW—like its competitors Audi and Mercedes—is hot to add to its small-car portfolio, and new information suggests that the Munich-based firm could be planning as many as four new and/or rethought products to slot below the 3-series by 2015.

For enthusiasts, certainly the most exciting prospect is the possibility of a 2-series. Just this month, BMW filed U.S. trademark applications for the monikers 228, 230, and 235. The -28, -30, and -35 suffixes are currently affixed to six-cylinder engines in BMW’s other cars, a strategy that could carry over to the nascent 2, although it wouldn’t surprise us if such a car arrived with four-cylinders among the powertrain options. (BMW hasn’t stuck to a straight badge-to-displacement naming strategy for some time.) Either way, our sources tell us that the car is likely to be rear-wheel drive. All of this also puts BMW’s June trademark application for “M2″ in some very exciting context.

How does this square with the current 1-series? In mid-2011, the current 1-series hatchbacks will get a heavy face lift. It’s possible that, starting then, coupes on that RWD platform will adopt 2-series badging. More probable, though, is that once the 1-series switches to a front-wheel-drive platform—a change widely expected to take place around 2015—BMW would launch the 2-series as its entry-level rear-driver. Our guess is that the 2-series would be a two-door coupe/convertible only, at least in our market.

Baby Bimmers (Yes, Plural) on the Way

BMW Megacity Vehicle (artist's rendering)

But we’re not done yet. Beneath that front-drive 1-series, BMW is planning two more models. Smallest in size will be the all-electric Megacity—which, as you might have guessed, is a city car (although it’s said to be bigger than a Mini). A more conventional entry below the 1-series is on the way, too: a Ford Fiesta–sized front-wheel-driver. That vehicle and the 1-series are likely candidates to offer a new gasoline-electric hybrid powertrain, which BMW recently announced will be jointly developed with Peugeot-Citroën. The companies already collaborated on gas four-cylinders for front-wheel-drive applications (it’s in the Mini Cooper), and this new hybrid system likely will leverage the next generation of that family.

As usual, this influx of information answers some questions about BMW’s plans but raises more: Will Saab utilize one of the front-wheel-drive platforms for its upcoming small car? Will the Swedish company (and BMW’s own Mini) have access to the hybrid technology? And most important of all, if the M2 ever emerges, it’ll have a stick, right?